Electric switch.



WITNESSES fia /37l L. J. PIERCE. ELECTRIC SWITCH. APPLICATION FILEDSEPT. 24, 1912.

Patented May .20,v 1913.

W. @fm

.DONNIE J. PIERCE,

OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WINDOW GLASS MACHINE COMPANY,OF PITTSBURGH, PENNSYLVANIA, A COPH`D^MTON F NEW J ERSEY.

Specification of Letters Patent.

ELECTRIC SWITCH.

' Patented May 20.11913.

Application filed September 24, 1912. Serial No. 722,028.

To all whom t may concern: Be it known that I, BONNIE J. PIERCE, aresident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented a new and useful, Improvement'` in ElectricSwitches, ofwhich the following is a full, clear, and exact description,re erence being had to the accompanying drawings, forming part of thisspecication, 1n which-.- v

Figure away, of

"-' 1 is a side view, partly broken a double-throw switch embodying myinvention. Fi 2 isA section of the same on line II-II o Fig. 1. Figs.3and .4 are details showing a modification of a portion of the switch. v

My invention has lrelation to electric switches; and is designed ltoprovide means of simple and effective character for insuring a goodelectrical contact betweenv the movable, or blade member of the switchand the terminal member to which itis attached, at the time when suchcontact is most necessary. .Myinvention also provides means of thischaracter which remains elective notwithstanding wear onfthe pivotalconnection between the movable or blade member and the terminal to whichit is pivoted.

The nature of my invention willbe best understood by reference to theaccompanying drawing, in which I have shown the preferred embodimentthereof, and which will now be described, it being premised,

however, that various changes can -be made 35 in the details ofconstruction and arrangement of the several parts without.departing fromthe spirit and scope of my invention,

as deiined-in the appended claim.

In these drawings, the numeral 2 designates the base 'of the switch, ofany suitable or-usual character,'and which is provided with threeterminals 3, 4 and 5. Each of these terminals is preferably formed intwo sections having a screw. connection at 6, as 45 -shownin Fig. 2, andclamping the vbase between them. The upperportion 4a of the centralterminal 4is formed with a slotor socket 7 to receive the lower end ofthe shank 8 of the switch handle 9, -said shank being pivoted in saidsocket on the bolt or screw 10. 11 are switchlblades which are shown asforming a part of blades being adapted to enga'gethe upper portion of'the terminal 3 and .the ot er these contact plates has a forked portion`14 at its upper end, these forked portions yopen position shownv inFigs. 1 and 2, and

reducing the Shanks, one of said l blade the upper portion oftheterminal 5. l

Secured to opposite sides of the upper portion 4* of the centralterminal 4, by means ofthe bolt or screw 10 and another bolt or screw12, are contact plates 13. Each of each forming a cage for a contactball 15. The contact balls project loosely through openings in the innermembers of the fork and contacting with the segments lof the shank 8.These segments areprovided each with a central depression 17 adapted toreceive the balls when the switch is in thev with other similardepressions 18 which receive the balls when the switch is in one Vor theother of its closed positions.' The engagement of the .balls with thecentral depressions 17 of the segments tends to .hold the switch in itsopen position; but during the time that theswitch is being moved fromits open position to one or the other of its closed positions, the ballshave a minimum contact with the segments 16, thereby the friction ofmovement to a minimum. When either of the blades 11 engages with itscoperating terminal, the balls snap into the corresponding enddepressions 18, which increases the contact surface between the ballsand segments and insures a ood electrical contact while the switch is cosed, the contact members 13 being of sprin character. r

' In the mo iication shown in Figs. 3 and 90 l 4, instead of providingthese contact members 13 with forks at their upper ends by securinseparate p ieees thereto, their upper en s are bent backwardly andinwardly, as shown' at 13a to form the ball-containing cages. l

The advantages of my invention will be apparent to those skilled in theart, since it provides a switch in which the maximum electrical contactis obtained when the switch is in either of its closed positions and notwithstanding considerable wear which may occur at the switch pivot.

While I have shown my invention as applied to a double-throw reversingswitch,

.it is obvious that it is also applicable to switches` of various otherforms. I claim: l An electric switch having a terminal member anda bladepivoted thereto, ,said terminal member having parallel spring oonbladeis in certain positions, substantially tact members between which theblade is as described. Y 11 adaptedv to move, and each of the said con-In testimony whereof, I have hereunto set tact members having aball-retainin seat or my hand.

5 cage near its free end portion, toget er with LONNIE J. PIERCE.

balls seated therein and adapted to Contact Witnesses: with the blade,the latter having depressions ROBT. J. WHALEN,

td reoeive portions of the balls when the WM. L. WARDLE.

